How to add TemplateField created in .aspx markup to GridView column in code behind?

Question

Basically, I want a button that adds a new column with my controls (i.e. TextBox, DropDownList) to my GridView.

Already seems simple enough with this:

protected void btn_AddColumn_Click(object sender, EventArgs e)
{
    TemplateField MyTemplateField = new TemplateField();
    gv_SupplierPrices.Columns.Add(MyTemplateField);
}

Say I want to add this markup:

<asp:TemplateField>
    <ItemTemplate>
       <table style="width:100%;">
          <tr>
             <td><asp:TextBox ID="tbox_ItemPrice" runat="server"></asp:TextBox></td>
          </tr>
       </table>
     </ItemTemplate>
</asp:TemplateField>

Here's the problem. How do I use a TemplateField I created in markup on my .aspx page and add it to my new column on code behind? I don't know and don't want to create my TemplateField on code behind because I will not be able to create elaborate or fancy markups. They will just look like controls that are next to each other. It's very ugly.

P.S. If anyone is curious as to what I'm actually making, I'm basically turning my GridView into an Excel-like gridsheet. New columns represent a supplier and each row represents an item the supplier is selling. They want it that way because it's easier to compare prices side-by-side whilst they're filling it up.

---

Update: I already figured it out. I can simply call the column of my GridView from codebehind that represents the TemplateField I created in markup, then I add it.

<asp:GridView ID="gv_SupplierTable" runat="server" AutoGenerateColumns="False" 
                        DataKeyNames="Id" DataSourceID="TestTable_DS">
                        <Columns>
                            <asp:BoundField DataField="Id" HeaderText="Id" InsertVisible="False" 
                                ReadOnly="True" SortExpression="Id" />
                            <asp:BoundField DataField="AccountType" HeaderText="AccountType" 
                                SortExpression="AccountType" />
                            <asp:TemplateField AccessibleHeaderText="MyTemplateFieldCreated in Markup">
                                <ItemTemplate>
                                    <table style="width:100%;">
                                        <tr>
                                            <td><asp:TextBox ID="tbox_ItemPrice" runat="server"></asp:TextBox></td>
                                        </tr>
                                    </table>
                                </ItemTemplate>
                            </asp:TemplateField>
                        </Columns>
                    </asp:GridView>

Then in codebehind, I can access that column that represents the TemplateField created in markup and add it again on button click, like a new copy:

    protected void btn_AddColumn_Click(object sender, EventArgs e)
    {
    DataControlField newColumn = this.gv_SupplierTable.Columns[2]; 
                                 //this column at index #2 from my GridView represents                  
                                 the TemplateField created in markup since the columns  
                                 at index #0 and index #1 are DataBound.
    gv_SupplierTable.Columns.Add(newColumn);
    }

Answer 1

You can toggle the visibility of each column.

gv_SupplierPrices.Columns[10].Visible = true;

Answer 2

In your position, I'd consider biting the bullet and investigating creating templated fields programmatically. It would be a nuisance, but once you were done, you'd be done. Of course, you'd want to abstract them away into a helper class or separate control.

Answer 3

Here are a couple examples on dynamically adding a column to your GridView:

protected void Page_Init(object sender, EventArgs e)
{
    btnAddColumn.Click += new EventHandler(btnAddColumn_Click);

    BoundField temp = new BoundField();
    temp.DataField = "Source";
    temp.HeaderText = "Source";
    temp.SortExpression = "Source";

    gv.Columns.Add(temp);
}

void btnAddColumn_Click(object sender, EventArgs e)
{
    TemplateField temp = new TemplateField();
    temp.HeaderText = txtNewColumn.Text;

    txtNewColumn.Text = string.Empty;

    gv.Columns.Add(temp);
}

ASPX:

<div>
    <asp:TextBox ID="txtNewColumn" runat="server" />
    <asp:Button ID="btnAddColumn" runat="server" Text="Add Column" />
</div>
<asp:GridView ID="gv"
    runat="server"
    AutoGenerateColumns="False"
    DataSourceID="dsExceptions">
    <Columns>
        <asp:BoundField DataField="Message" HeaderText="Message" />
    </Columns>
</asp:GridView>

<asp:ObjectDataSource ID="dsExceptions"
    runat="server" 
    SelectMethod="GetExceptions"
    TypeName="WebApplication.Data.MyDataContext" EnablePaging="True" 
    SelectCountMethod="GetExceptionCount" >
    <SelectParameters>
        <asp:Parameter Name="maximumRows" Type="Int32" />
        <asp:Parameter Name="startPageIndex" Type="Int32" />
        <asp:Parameter Name="startRowIndex" Type="Int32" />
    </SelectParameters>
</asp:ObjectDataSource>

My ObjectDataSource is just getting a collection of Exceptions I create, so you can ignore that part of the code.

So I'm adding a column via code in the Page_Init handler, as well as adding a column with the header text set to the text in txtNewColumn. One thing about this, though, is that if you refresh the page, it will lose the columns you've added with the button on the page. You'll want to add some code in the button click event handler to store the new columns, so they're always in the GridView when it reloads. Since it sounds like the columns represent a vendor, you might just want to add a form for someone to add a vendor to your system. The vendor gets saved in a database/datastore somewhere, and in the Page_Init, you get all the vendors from that datastore and loop over them, creating the template fields for the vendors. It would be something like this:

// I am just creating a list here, you would pull the vendor names in from the 
// datastore here instead.
var vendors = new List<string> { "Vendor A", "Vendor B", "Vendor C" };
foreach (var vendor in vendors)
{
    TemplateField temp = new TemplateField();
    temp.HeaderText = vendor;
    gv.Columns.Add(temp);
}